document.write( "Question 850929: if cos t=0.4, with t in quadrant IV, find tan(t+pi) \n" ); document.write( "
Algebra.Com's Answer #512496 by lwsshak3(11628)\"\" \"About 
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if cos t=0.4, with t in quadrant IV, find tan(t+pi)
\n" ); document.write( "cos t=0.4=2/5( In quadrant IV in which cos>0, sin<0, tan<0
\n" ); document.write( "
\n" ); document.write( "tan t=sin/cos=\"-sqrt%2821%29%2F2\"
\n" ); document.write( "Identity:
\n" ); document.write( "tan(t+π)=-√21/2+0/(1-√21/2*0=-√21/2
\n" ); document.write( "..
\n" ); document.write( "calculator check:
\n" ); document.write( "cos t=0.4
\n" ); document.write( "t≈293.58˚
\n" ); document.write( "t+π≈473.58˚
\n" ); document.write( "tan(t+π)≈tan(473.58˚)≈-2.2910
\n" ); document.write( "Exact value=-√21/2≈-2.2912 \n" ); document.write( "
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